Spectroscopie des noyaux lourds Dubna GABRIELA Tunnel detectors

Spectroscopie des noyaux lourds @ Dubna GABRIELA Tunnel detectors Germanium array Position-sensitive implantation detector SHELS • Commissioning of GABRIELA@SHELS: 2016 K. Rezynkina et al. , Ph. D thesis (2016) [PRC 97 (2018) & NIMA 844 (2017)] • Full Characterisation & simulation SHELS recoil separator R. Chakma (Ph. D 2017 -2020), submitted to EPJ A (2020) 26/06/2020 Journée AP du pôle nucléaire 1

Recent results: 2017 -2020 • Observation of a cascade of 2 isomers in 255 Rf (R. Chakma, Ph. D thesis IJCLab, article in preparation) and 255 No (K. Kessaci, Ph. D thesis IPHC) • First in-flight spectroscopy & observation of high K isomer (4 qp) in 256 No (K. Kessaci et al. , article in preparation). Our first result using a very asymmetric reaction (22 Ne+238 U). • Fine structure alpha decay, gamma & ICE spectroscopy of 257 m, gs. Rf->253 No: first identification of 11/2 - state in 253 No (K. Hauschild et al. , to be published) • Decay spectroscopy of the known high-K isomer in 250 No and measurement of its fission hindrance (A. Lopez-Martens, article in preparation). Analysis of the fission hindrance of the K-isomers in 254 No is on going. • (E*, I, p) of lowest-lying high-K isomer in 256 Rf (K. Hauschild, to be published) 26/06/2020 Journée AP du pôle nucléaire g & ICE decay of 250 m. No 2

Perspectives To get the full picture of 255 Rf: fine structure alpha decay of 259 Sg->255 Rf 6 week experiment Follow up on 257 Rf->253 No decay experiment: (re)study the decay of 253 m. No 4 week experiment (ALM et al. , Nucl. Phys. A 852 2011) Upgrade of the entrance quadrupole triplet of SHELS [delivery COVID delayed]: 1 week transmission test (later: continue the decay spectroscopy program using assymetric reactions more neutron rich eg 22 Ne+238 U, 242 Pu) Participation in the investigation of deep inleastic channels in the 48 Ca+243 Am reaction (run stopped due to covid crisis – probable restart in Autumn) Upgrade of GABRIELA (clover + 4 coax-> 5 clovers, new chamber & shielding, improved X-ray detection) => needs to be qualified 26/06/2020 Journée AP du pôle nucléaire 3

Perspectives (exploitation) in numbers… 2 permanent staff + 1 post-doc (P 2 IO ? ) Missions (253 No experiment): Per diem Tickets days Missions (259 Sg -> 255 Rf experiment): days # 24 Per diem working meetings Per diem Tickets conference equipment missions A B C 40 550 informatique D 2880 3300 A B C 4 week experiment + set-up + calibs => 1 week set-up + 1 week dismantle + calibrate + tests D 3 40 3240 6 week experiment + set-up + calibs (ensure 100% coverage) 8 550 4400 1 week set-up + 1 week dismantle + calibrate + tests 28 3 12 40 550 3360 6600 3 people @ 4 x 1 week 5 3 3 40 550 600 1650 1 meeting at Dubna for discussions 1 1500 ALM already invited to NN 2021 (others off SNBA) 27 Tickets Missions (tests: Tx/electronics/DAQ) Per diem Tickets item cost 3 6 bureau days A B C Hard discs Laptop D 500 2000 ~27. 5+2. 5 = 30 k Will submit an IRP request hopefully to reduce this by 7 k 26/06/2020 Journée AP du pôle nucléaire 4

Report on front-end electronics upgrade Need new preamps capable of providing energies of the ICE, alpha-particles, recoils, scattered beam and fission-fragments in ONE single range => ~40 ke. V to ~200 Me. V Despite non-optimal conditions FWHM ~8 ke. V [in 180 Me. V FS] (NB PA is ~3. 5 – 4 ke. V) 133 Ba Experiencing a few COVID delays and expenses => DSSD being sent from FLNR Unfortunately will run 5 k over? budget (this year or next ? ) 26/06/2020 Journée AP du pôle nucléaire 5

A SHEXI Development: identify SHE via characteristic L X-rays L? There always L X-rays for converted transitions. Not the case for K (eg E 1) The solution is to use ~1. 5 mm thick Si detectors with very high resolution ASICs Geant 4 simulations x 10 photon energy [ke. V] 26/06/2020 Resolution simulations from XGLabs assuming 10 p. F for different ILEAK (v. high resistivity lower depletion V lower I) Journée AP du pôle nucléaire 6

A SHEXI example: 48 Ca+243 Am 288 Mc 284 Nh 280 Rg 276 Mt Geant 4 simulations for a 60 day SHE factory run Ge array Determine Z one of the daughters in the Mc decay chain L X-rays Si array First proof of Z in the isolated « cold » fusion SHE region (S 3 mass later) Cost for large detector proof of principal: [IPHC requests funds for a prototype detector] IJCLab: 15 k (minimum ASIC order + PCB + det support + cables) 26/06/2020 Journée AP du pôle nucléaire 7

Summary: TOTAL IJCLab demand 50 k Dubna Missions (253 No experiment): Per diem Tickets bureau days # 24 Missions (256 No or 261 Sq experiment): days Per diem 27 Tickets Missions (tests: Tx/electronics/DAQ) Per diem Tickets working meetings Per diem Tickets conference days 28 5 3 6 equipment missions informatique item cost A 40 550 B D A B C 2880 3300 C 4 week experiment + set-up + calibs => 1 week set-up + 1 week dismantle + calibrate + tests D 3 8 40 550 3240 4400 3 12 40 550 3360 6600 3 people @ 4 x 1 week 3 3 40 550 600 1650 1 meeting at Dubna for discussions 1 1500 ALM already invited to NN 2021 (others off SNBA) A B C 6 week experiment + set-up + calibs (ensure 100% coverage) 1 week set-up + 1 week dismantle + calibrate + tests D Hard discs Laptop 500 2000 SHEXI @Orsay: 0. 4 ke. V FWHM resolution (minimum order) ASICs + PCB + LV board + cables (in/ext) "jury rig" remaining strips + mechanics 15000 TOTAL Totals (Dubna) 0 20000 27530 2500 ==> ~50000 Possible reductions: 5 k (10 k « loan » to AGATA core) and 7 k IRP 38 k ? 01/03/2020 Mon exposé - Lieu - Titre 8